In an image forming apparatus in which a developing device using a powdery toner visualizes an electrostatic latent image formed on an image carrier, the toner in the developing device is consumed with formation of images. Thus, conventionally, an image forming apparatus has been known which includes a toner supply device including a toner container as a powder container containing a toner, and configured to supply the developing device with the toner contained in the toner container.
In a toner supply device thus configured, an opening formed at an end of the toner container is closed by a plug member to prevent a toner in the toner container from spilling out during storage or transportation, and the plug member is removed when the toner supply device is mounted to a main body of an image forming apparatus. Such a toner container, and a toner supply device and an image forming apparatus which include the toner container are disclosed in Patent Document 1, for example.